After all the positive talk about John Abraham's return, the Arizona Cardinals placed the linebacker on injured reserve list Friday due to a concussion, ending his 2014 season and possibly his NFL career.

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It's the latest plot twist in a bizarre couple weeks for Abraham. The NFL's active leader in sacks suffered a concussion in Week 1, contemplated retirement and Bruce Arians said Abraham's heart wasn't "in the game anymore."

Abraham had reportedly been suffering from memory loss for more than a year before the Week 1 concussion.

It could be the end of the road for the 36-year-old. If it is, count Abraham as having a great NFL career after being picked in the first round by the New York Jets in 2000. His 133.5 sacks in a 15-year career place him ninth on the NFL's all-time list.

The loss is problematic for the Cardinals, who will sorely miss the pass rusher. Abraham earned 11.5 sacks last season and was the team's one true edge rusher.